Co-acting wheels for feeding multifilament strands



Dec. 1, 1959 G. SLAYTER ETAL 2,915,170

CO-ACTING WHEELS FOR FEEDING MULTIFILAMENT STRANDS Filed Feb. 3, 1955 2 Sheets-Sheet 1 IN V ENTORS:

Dec. 1, 1959 s. SLAYTER ETAL 2,915,170

(IO-ACTING WHEELS FOR FEEDING MULTIFILAMENT STRANDS Filed Feb. 3, 1953 2 Sheets-Sheet 2 INVEN TORS Game: J/agfer F" BY R 575/)? ATTOR NAtY-f United States Patent CO-ACTING WHEELS FOR FEEDING MULTIFILAMENT STRANDS Games Slayter, Newark, Ohio, and William R. Steitz, Anderson, S.C., assignors to Owens-Corning Fiberglas Corporation, Toledo, Ohio, a corporation of Delaware Application February 3, 1953, Serial No. 334,806

The terminal portion of the term of the patent subsequent to January 3, 1973 has been disclaimed 4 Claims. (Cl. 203-220) This invention relates to co-acting rotary wheels for feeding strands at high linear speeds and, more particupast. Such pulling wheels have been made with resilient surfaces in order to permit the wheels to be set so that their surfaces are compressed and thus tightly grasp the strand being fed.

Where the strand being fed consists of a multiplicity of'filaments as, for example, in the glass fiber arts, where the strand may comprise 200 or more individual filaments attenuated together to form a strand, and where the strand is fed at extremely high speeds, say, in the order of 10,000 feet per minute, smooth surface pulling wheels have several serious faults which, under, certain conditions, render them virtually useless.

Where the wheels are pressed tightly together in order to insure sufiicient traction both to feed the strand and to pull the individual fibers forming the strand from their forming orifices, there is a tendency on the part of the strand to cling to one or the other surfaces of the two co-acting pulling wheels. This tendency to cling is generally referred to in the art as licking.

Licking may involve the entire strand or it may involve only a few of the fibers. In the latter case, some of the fibers may cling to each of the wheels, or some may cling and the remainder continue to be fed. In either of these latter cases, the integrity of the strand itself is destroyed, the fibers which lick on the wheels are torn away from the strand and may, in fact, be wrapped around one or the other, or both, of the pulling wheels.

Whether merely a few fibers or the entire strand licks on one or more of the Wheels, the feeding operation must be stopped because the feeding or pulling operation may I be taking place at a speed in the order of that mentioned above, and a substantial number of wraps on turns of the licked fibers or strand may be made before an operator can stop the machine. The operator must then cut away the licked fibers or strand, restore the integrity of the strand and start feeding again.

Where the feeding wheels are being employed for simultaneously pulling the fibers from fiber forming orifices, the necessity for periodically stopping the pulling opera tion in order to clear the wheels results in loss of time and product. The streams of glass pouring through the orifices, and from which the individual fibers are pulled, congeal slightly forming soft beads which increase in size until their weight is sufficient to form globules which drop oif trailing a thin fiber behind them. Such globules must, of course, be removed from the apparatus manually and the clean flow of a fiber reinstigated.

Not only does the licking of the individual fibers around the wheel require that the pulling operation be interrupted 2,915,110 Patented Dec. 1,

"ice

to permit their removal, but it may injure the pulling wheel by cutting into its surface. Frequently when a strand or some of its fibers lick to a pulling wheel, it also results in the loss of a mass of fibrous material which may be scattered over the driving wheels or associated machinery and the loss of the time required to clean up the working area and dispose of the spoiled strands.

It is, therefore, the principal object of this invention to provide co-acting pulling wheels particularly effective for feeding multifilament strands and so designed that the strand and its fibers are rejected by the pulling wheels, thus reducing the tendency for the strand or any of its fibers to lick on the wheels.

It is another object of this invention to provide a pair of co-acting pulling wheels in which the linear length of strand being fed by the wheels is different from the length of the surface of the wheels to which the strand might adhere and thus the differential between the lengths which are adjacent each other prevents the strand or its fibers from traveling with, clinging to, and licking aroun the pulling wheels.

-It is a further object of this invention to provide a pair of co-acting pulling wheels which apply pulling force to all the individual fibers of a multifilament strand.

It is yet another object of this invention to provide a method for feeding a multifilament strand by alternately deforming the strand in opposite directions and progressing the deformities along the path of feeding of the strand.

A still further object of this invention consists in providing a method for feeding a continuous multifilament strand by engaging said strand between the spaced pro'- truding portions of opposed, interdigitated instrumentalities and simultaneously moving the protruding portions along the path of movement of the strand.

The mode of achieving these objectives and a fuller understanding thereof will become apparent from the specification and the drawings, in which:

Fig. l is a simplified diagrammatic showing of apparatus employed for pulling and feeding multifilament glass fiber strands and illustrating pulling wheels embodying the invention as employed therewith.

Fig. 2 is an enlarged fragmentary view in elevation of the pulling wheels shown in Fig. 1 and illustrating more clearly how the surfaces engage each other and with a multifilament strand being fed thereby.

Fig. 3 is a view similar to Fig. 2 but of a modification of the invention employing a surface configuration different from that shown on the wheels illustrated in Figs. 1 and 2. l

Fig. 4 is a fragmentary vertical sectional view taken substantially on the line 4-4 of Fig. 2.

Fig. 5 is a view similar to Fig. 4 but taken on the line 5 s of Fig. 3.

Fig. 6 is a fragmentary view in elevation with certain parts being broken away of a modified form of construction constituting still another embodiment of the invention and illustrating the formation of pulling wheels embodying the invention by the proper association of multiple parts. V

Fig. 7 is a fragmentary vertical sectional view taken on a plane through the axis of one of the pulling wheels shown in Fig. 6. r

Multifilarnent glass fiber strands may be formed, as shown in Fig. 1, by providing a source of molten glass as, for example, a tank 10 having a plurality of nipples 11 each of which has a small orifice through which a fine stream of molten glass is'caused to flow. By approlinearly at high speed, beingattenuated into individual fibers 12 and gathered by a gathering eye or similar means 13 to form a multifilament strand 14.

The linear feeding of the multifilament strand 14 and thus the formation of individual fibers 12 is accomplished according to the invention by feeding the strand 14 between the 'bite of a pair of co-acting rotating pulling wheels --15 shown in enlarged scale in Fig. 2.

Each of the pulling wheels 15 has a hub 16, a web 17 and a tire-like rim 18. In the embodiment of the invention shown in Figs. 2 and 4, the rim 18 is molded from, for example, rubber or similar resilient material to provide a scalloped outline consisting of projecting portions 19 and alternating valleys 20. The tire 18 may be bonded or otherwise secured to the web 17 of the pulling wheel '15 as shown in Fig. 4. i The strand 14 (Fig.2) is led between the bite of the pulling wheels 15 where it is laterally deformed by the engagement of a projection 19a on the one pulling wheel 15 with a valley 20a on the other pulling wheel 15. The hubs 16 and the axes of the pulling wheels 15 are so spaced from each other laterally that the projections 19 and valleys 20 tightly engage each other to deform the resilient material from which the tire 18 is fabricated. By reason of the scalloped configuration provided by the .projections 19 and valleys 20 the strand 14 is given a generally sinusoidal form as it leaves the bite between the pulling wheels 15.

In the operation of pulling wheels 15 designed according to the showing of Figs. 1, 2 and 4, it has been found that the strand 14 does not cling to either of the pulling Wheels nor does it' tend to split allowing its individual fibers to cling to the surfaces of the tire 18 and to lick" around the pulling wheels 15. It is believed that this results from the following theory. Because of the scalloped peripheries of the pulling wheels 15, the linear dis tance around the one of the wheels 15 including the sur faces of the projections 19 and valleys 20, is substantially greater than the circumference of a circle concentric with the pulling wheel 15 and tangent to the projections 19 at their greatest altitude. force acting on the strand 14 where engaged with either or both of the pulling Wheels 15, the strand 14 or its fibers would not tend to cling to the surface of the tire 18 in the valleys 20 but if the fibers making up the strand 14 were to lick around either of. the Wheels 15 they would lie in a general circular shape engaging only the sum of the scalloped peripheries) a greater linear length of strand passes between the pulling wheels 15 for each complete revolution, for example, than would be required to stretch around either of the pulling wheels contacting only the summits of the projections 19.

In order, therefore, for a fiber from thestrand 14 or for the strand 14 itself to cling to one of the pulling "wheels 15 and to lick therearound, it would be necessary for the strand either to slow down, insofar as the linear length being fed is concerned, or to form in loops away from contact with the surfaces of the pulling wheels 15. Any tendency of the fibers of the strand 14 or the strand 14 itself to cling to the surface of one of the pulling wheels, is overcome by the centrifugal force tending to keep it on the summits of the projections 19 and by its extra length. If the strand 14 or its fibers 12 contact only the'summ'its of the projections 19, insufficient contact with the tire 18 is provided to result in adhesion of either'thestrand or its fibers to the wheel.

Although it is virtually impossible precisely to determine the configuration taken by the strand at the time it leaves contact with the pulling Wheels 15, and thus Fig. 2

lbeyondttheipullingwheels:to agathering pointor to.sub-

Because of the centrifugal I sequent handling equipment. With the pulling wheels 15 running in synchronism by reason of the inter-meshing of the projections 19 and valleys 20, licking is virtually eliminated. Observation of the operation of pulling wheels embodying the invention, as shown in Figs. 1, 2 and 4, reveals that the strand 14 is not split but is fed as a unit through the bite of the pulling rollers, i.e., all of the fibers are fed together and at the same speed and configuration.

It has been found that less compressive force between the surfaces of the scalloped periphery feeding wheels designed according to the invention is required than is required where the perimeters of the wheels are circular. This improvement is thought to result from the fact that the scalloped configuration provides a longer line of contact between the surfaces of the pulling wheels 15 and the strand being fed than is possible where two smooth periphery pulling rollers are employed and the strand runs substantially tangentially thereto.

When smooth, circular periphery, wheels are used, they may be squeezed tightly together to compress the resilient tire material in the bite between the wheels to provide for a longer line of contact with the strand 14. However, the considerable compressive force required to accomplish this lengthening of the contact distance is deleterious to the life of the rims or tires on the pulling wheels and the excessive compression of the treads may cause the strand to pull apart.

The embodiment of the invention shown in Figs. 3'and 5 illustrates how a scalloped periphery of an entirely different configuration operates to accomplish substantially the same improved results as those accomplished by the first embodiment of the invention shown in Figs. 1, 2 and 4. In the apparatus of Fig. 3 two pulling wheels 21 are shown as having webs 22 and tire-like rims 23. In this instance the rims 23 consist of projections 24 having arcuate profiles and all lying on the same arc concentrio with the pulling wheels 21, spacedby cylindrically shaped depressions 25.

The rim 23 may be bonded (Fig. 5) or otherwise secured to the web 22 of the pulling wheel 21 and in'Fig.5 the pulling wheel 21 is shown as being formed of reinforced resinous material. The material from which the wheel 21 is made does not constitute a part of the instant invention and it may be reinforced resinous mateterial or other lightweight material 'having structural integrity, for example, aluminum, magnesium and. similar materials.

The radii of the cylindrical depressions 25 areall the same and the depth and cordal length of the depressions 25 are such that when a depression 25a and a projection 24:: are intermeshed at the bite between the pulling wheels 21, the end of the projection 24a is slightly deformedand pressed into the surface of the depression25a to provide for tight grasping of the strand 14a being fed therethrough.

The embodiment of the invention shown in Figs. 3 and 5 may more sharply deform the strand 14a being fed than does that shown in Figs. 1, 2 and 4 and it may haveaa lesser line of contact with the strand between the projections and depressions forming the scalloped peripheries of the pulling wheels. Again however, the disparity be tween linear length of the strand being fed and thetotal circumferential surface of the pulling wheels is considerable and again, as in the first embodiment of the invention, there is no discernable tendency for the strand 14a or its individual fibers to cling to the surfaces of the pulling wheel 21, to be split or to lick on the wheels.

Formation of pulling wheels embodying the invention as shown in Figs. 2 and 3 with unitary continuous resilient rims or tires 18 and'23 is entirely satisfactory 'froman operation standpoint but requires the empioymentoflarge molds for the molding of the resilient rims and creates some friction and heat causing relatively frequent replacement of the pulling wheel .rims as compared .to a

further modification or the invention shown in Figs. 6 and 7.

In the third modification of the invention as shown in Figs. 6 and 7, two co-acting pulling wheels 26 have hub sections 27 (Fig. 7), formed webs 28 and rims 29. In this embodiment of the invention the rims 29 serve to mount tires 30. The tires 30 are illustrated as being formed from reinforced resinous material and as mounting resilient, semi-cylindrical lugs 31. Each of the lugs 31 has a semi-cylindrical main body 32, shank 33 and a flange 34. The flange 34 and shank 33 serve to retain the lug 31 in the tire 30 with the generally diametric surface of the body 32 lying on the arcuate surface of the tire 30.

It will be observed in Fig. 6 that the lugs 31 are circumferentially spaced from each other around the peripheries of the tires 30 and, thus, the pulling wheels 26, a distance such that each lug 31 on one of the pulling wheels 26 intermeshes or interdigitates with two lugs on the other pulling wheel 26 in a manner substantially identical with the intermeshing of the projections 19 and 24, respectively, shown in Figs. 2 and 3, with the valleys 20 and 25, respectively, shown in those figures.

As is the case with the earlier described embodiments of the invention, the axes of the pulling wheels 26 are so spaced from each other that each of the lugs 31 is deformed slightly by engagement with the arcuate surface of the other one of the tires 30 between the lugs 31 on the other one of the pulling wheels 26 in grasping and feeding a multifilament strand 14b.

All of the embodiments of the invention disclosed have in common the lateral deformation of the strands being fed and the resultant inhibition of the licking tendency. In addition to this improved characteristic, pulling wheels embodying the invention achieve an improved pulling action because of the snubbing of the multifilament strand caused by its lateral displacement by the intermeshing higher and lower portions of the peripheries of the pulling wheels.

It appears that when a multifilament strand is merely grasped, for example, between the thumb and forefinger and the strand is pulled longitudinally the outermost fibers of the strand tend to feed quite easily, there being suflicient friction between the grasping surfaces and these outermost fibers. In order, however, to feed the inner fibers there must either be enough friction between adjacent fibers or the entire strand must be tightly enough squeezed so that the outer fibers will not slip longitudinally with respect to the inner fibers. This partially explains the necessity for so tightly compressing a strand between two smooth circular periphery pulling wheels.

In contrast to the effect of merely grasping the strand between a thumb and forefinger, for example, snubbing a multifilament strand around a finger transfers pulling force to all of the fibers in the strand. This is an effect analogous to that achieved by the rapid and sudden displacement of the strand by each of the intermeshed higher and lower portions of the scalloped periphery of pulling wheels embodying the invention.

The use of pulling wheels embodying the invention for the longitudinal feeding of multifilament strands at high linear speeds thus improves the operation not only by feeding all of the fibers of the strands uniformly (snubbing) but it virtually eliminates licking of the strands or their fibers on the pulling wheels and the de' structive and expensive strand separation or disintegration caused thereby; saving both labor and material and resulting in longer wheel life, less damage to the strands being fed and better control over the operation as a whole.

We claim:

1. Apparatus for linearly feeding a multifilament, un twisted strand comprising a plurality of fine fibers oriented and laterally compacted into close parallel relationship,

said apparatus comprising a pair of pullingelements having interdigitated, undulatory surfaces at least one of which is resilient, means mounting said elements so that the surfaces are pressed tightly together around and against opposite sides of said strand, means for guiding said strand between the engaged undulatory surfaces of said pulling elements, means for moving said pulling elements for drawing and projecting said strand along a generally linear pathway with an impetus greatly in excess of that to be achieved by said strand under free fall, said mating undulatory surfaces acting to pull said strand and for laterally displacing said strand upon opposite sides of the center line of such pathway upon departure of said strand from the bite between said pulling elements.

2. Apparatus in accordance with claim 1 in which said pulling elements comprise a pair of rotary elements having interdigitated undulatory surfaces and in which the higher surfaces of one of said elements are pressed tightly against'the lower surfaces of the other of said elements in the bite between said elements.

3. Apparatus for feeding an untwisted strand under tension, said strand consisting of a high number of fine, continuous filaments that are oriented and laterally compacted into close parallel relationship and that tends to separate with at least some of its filaments clinging to a feeding surface, said apparatus comprising a pair of rotary elements having complementary undulatory surfaces, at least one of said surfacesbeing resilient, means for mounting said elements on spaced parallel axes with surfaces thereof in tight mated engagement in the bite between said elements, means for guiding said strand into the bite between said elements, the axes of said elements being so spaced that during rotation said surfaces are in engagement with each other around said strand and on opposite sides of said strand for applying tension for feeding said strand along a generally linear pathway that is tangential to the paths of movement of said surfaces and for deforming said strand alternately to opposite sides of said linear pathway while in engagement between and with said surfaces, and means for rotating said elements at such high speed that said strand is projected from between said surfaces and departs therefrom without clinging to said surfaces or either of them.

4. Apparatus according to claim 3 in which the surfaces of said elements are regularly scalloped and the higher surfaces of the scallops on each element are pressed tightly against the lower surfaces of the scallops of the other element in the bite between said elements.

References Cited in the file of this patent UNITED STATES PATENTS 2,030,252 Hale et al. Feb. 11, 1936 2,090,669 Dreyfus et al. ..1 Aug. 24, 1937 2,230,272 Slayter Feb. 4, 1941 2,291,289 Slayter et al. July 28, 1942 2,419,320 Lohrke Apr. 22, 1947 2,654,182 Courtney et al. Oct. 6, 1953 2,715,299 Steitz Aug. 16, 1955 2,729,030 Slayter Jan. 3, 1956 

